I also put these on my XDm and like them a lot.Some brands fit both. Others do not. I know Meprolight makes different sights for each. I have ML11420 and they are made specifically for the XDM. I choose these because they are the same profile as the stock sights.
Except for Truglo'sGo to the opticsplanet website. Plenty of choices, but nothing beats the Trijicon.